Process of producing elementary silicon and by-products.



STATES PATENT OFFICE.

FLORENTINE J. IA GHALSKE, OF PHILADELPHIA PENNSYLVANIA, ASS IGNOB OF ONE-- HALF 1'0 CHRISTOPHER OFFENHAUSEB, O1 PHILADELPHIA, PENNSYLVANIE.

1,062,982. No Drawing.

Specification of Letters Patent.

Application fled Kay 18, 1918. Serial No. 607,060.

Patented May 27 1913.

To all whom it may concern:

Be it known that I, FLORENTINE J. MA- CHALSKE, a citizen of the United States of America, and a resident of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Processes of Producing Elementary Silicon and By-Products, of which the following is a specification.

This invention has reference to a novel rocess of producing elementary silicon and y-products. This non-metallic element is never found in nature in the free state owing to its afiinigy to oxygen. It exists in nature very abun antly for instance in form of silicates in which the silicon is contained as silica SiO The silica in the silicates is combined for instance with aluminum oxid and water in the kaolin which thus is aluminous silicate. In other silicates the silica is combined with rare refractory'oxids for instance tungstous oxids or molybdenous oxids or it may be in form of a compound containing caesium.

The present invention has for its special purpose to roduce simultaneously the elementary sillcon and by-products by means of an electro-thermic process. The b products thus obtained consist of such so stances as are contained in the silicious compound used as a raw material. If for instance an aluminous silicate is used as a raw material such as kaolin the by-product kaolin is:

Si,O,,Al,H or the constitutional formula generally accepted is:

2SiO,.Al O .2H O.

Accordingl there are 56.6 parts by weight of sillcon and 54.2 parts by weight of aluminum contained in the molecule.

mining the quantity of carbon to be mixed with the silicious compound. This proportionate percentage of the carbon relative to the silica contained in the molecule of the silicious compound results in keepin the other component part of the molecufie intact which is one advantage of the process while a second advantage is the saving of.

power because one component part of the silicious compound is not decomposed.

The present process is carried into efiect in a suitably constructed electric furnace. A commercial furnace preferably of the resistance type, is advantageously employed of about 100 K. W., from 20-to 50 volts at 2000 to 5000 amperes. This variance in the electric power is suflicient for practically all thel silicious compounds used as a raw mater1a In order to render the invention entirely clear same will be described now with kaolin as an example of the raw material employed. The kaolin in its anhydrous state contains about 120.6 parts of silica and about 102.2 parts of alumina in the molecule. A proportionate percentage of carbon is added-to bind the oxygen of the silica of the kaolin onl The carbon employed is preferably pu verized coke which is free from sul ur. If a hydrous aluminous silicate is used same is made anhydrous by reducing it to powder by roasting and grindin same to drive off the molecular water he. ore the addition of carbon is made. According to the molecular weight 222.8 parts of the silicious compound require 48 parts of carbon for the reaction which takes place in this instance in accordance with the following equation:

From the above equation it is apparent tained in the raw material leaving thus the aluminum oxid intact. To start the reaction a. small quantity of sodium chlorid and sawdust in )roportions of about 1% of each is mixed with the furnace charge. This causes that the fusion of the alumina and the re duct-ion of the silica propagates itself uniformly throughout the entire uniformly mixed charge. The duration of the process in the furnace is about one hour. While still in a liquid condition the resulting molten mass is separated into its constituent parts by subjecting the furnace with the commercial products which may be further purified or not as'desired.

In case an ore is employed as a raw material which is composed of other constituents than the kaolin referred to hereinbefore as an example, tungsten silicate for instance is worked up then the process results in the formation of elementary silicon and tung-. stous oxids according to the composition of this compound. Likewise other compounds are obtained as by-products when the silidirectly to centrifugal action. a

2. The process of producing directly in separate condition elementary silicon and by-products from silicious compounds consisting in splitting up the compounds by electro-thermic fusion and subjecting the fused mass directly. to centrifugal action while allowing the current to pass at a voltage somewhat less than that used during the electro-thermic fusion of the said compounds.

3. The process of producing simultaneously elementary silicon and metallic oxids consisting in splitting up silicious compounds by electro-thermic fusion, and subjecting the fused mass directly to centrifugal action while allowing the current to pass at a voltage somewhat, less than that used during the electro-thermic fusion of the said compounds, separating thus the silicon from the metallic oxids by specific gravity.

Signed at New York, N. Y., this 10th day of May, 1912.

FLORENTINE J. MACIIALSKE.

Witnesses:

EMMA A. McCARnIcK, MARIE H. LEHR. 

